Subgrate drain basin filter

ABSTRACT

The present invention is a filter insert inside a storm water inlet with a grate cover and including an inlet with a combination of curb inlet and grate, and holds the insert within the inlet by means of a support inserted within a sleeve that rests directly upon the basin covers&#39; support.

This application in part discloses and claims subject matter disclosed in my earlier filed pending application, Ser. No. 09/991,733, Filed Nov. 20, 2001

BACKGROUND OF THE INVENTION

This invention relates to a filter for use inside storm water inlet basins, beneath perforated covers such as perforated manhole receptacles or a catch basins covered with grates.

Storm water collection systems are located throughout our city streets and parking lots providing flood control and drainage. The storm water needs to be as free as possible from pollutants before it enters our natural water systems such as streams. To ensure that our water sources are protected our handling of storm water is becoming more regulated. In order to meet these concerns, many inventions have been patented that provide an anti pollution filter insert system for catch basins and manholes. Most of these inventions are unnecessarily expensive. The present invention pertains specifically to storm water inlet basins with perforated top covers.

DESCRIPTION OF THE PRIOR ART

See above primary patent

SUMMARY OF THE INVENTION

Accordingly, my invention provides a filter with a support structure and filter basket which is inexpensive to manufacture, and is easy to install, remove, or service. Further objects and advantages of my invention will also become apparent from a consideration of the drawings and ensuing descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure IV is an exploded perspective drawing of my in subgrate basin insert for a combination grate and curb inlet including a cut away that shows a by pass opening.

Figure V is an exploded perspective of my subgrate basin insert with a discontinuous rod support structure.

Figure VI is a perspective drawing of my subgrate basin insert with four support bars.

DESCRIPTION OF THE PREFERRED EMBODMENTS

Insert for a Grate and Curb Inlet Combination

In the preferred embodiment of my invention the support structure comprises the right support bar 44, the left support bar 46, the front bar spreader 58, and the rear bar spreader 56. The support structure is typically made of eighteen gage galvanized sheet metal in an angle iron formation with a two inch width on both the horizontal and vertical angles. The right support bar is shown inserted in the bar sleeve. The front bar spreader 58 holds the support bars on their cover support ledges by jamming their vertical angle between the support bars while the bridge ear 42 holds the spreader in position. The rear spreader is inserted into the bar sleeve and is also in an angle iron form. It holds the ends of the support bars in place.

Both bar spreaders are approximately one inch shorter than the full width of the basin top opening. The length of the spreaders exceed the distance between the opposite walls of the inlet basin by approximately three inches. The rods rest flat on the cover ledges underneath the perforated cover when the cover is in place.

A bag assembly 54 comprises a filter basket 38 and two bar sleeves 48 and 49. The continuous sleeve 49 is one continuous length enclosing a right support bar 44 and its bottom right support arm 62, shown inserted inside the sleeve, and further suspending across to enclose a left bottom support arm 64 and the left support bar 46 when assembled. The bag assembly is attached to the support structure by means of the continuous sleeve 50 and the bar sleeve 48. These bar sleeves enclose the two support bars and bottom support arms and the rear bar spreader 56. The filter basket is made of a porous material with hydraulic openings smaller than the pollutants intended to be filtered from the storm water. In my preferred embodiment the bag assembly is made from a polypropylene geotextile fabric. However this filter may be made of many types of porous materials for example, cotton, burlap, fiberglass screen, stainless steel, galvanized steel, or aluminum mesh.

In my preferred embodiment one or more by pass openings 36 are located in the basin basket walls under a bridge flap 40. Bridge flap 40 bridges storm water over the bypass openings into the inside of a filter basket 38. Other bypass means may be utilized along with this support structure, for example a bypass looped between the support ledges under a metal bridge as shown in Figure I bridge 18. Another by pass opening could be added when necessary by inserting a vertical tubular outlet with the upper lip rising above the center inside floor of the filter basket.

In my preferred embodiment, when the apparatus is assembled, the combination of the right support bar and enwrapping sleeve rests directly upon the cover support ledge 52 and the left combination of the same rests directly upon a support ledge (not shown) essentially on the opposite side of the basin from ledge 52. There is no intervening support structure between this combination and the cover support ledge. The support ledges 52 are typically two inches wide and about two feet long. There are usually only these two supports in a combination curb and grate inlet basin. The bottom vertical angle of the support bars' angle iron formed on the support bars 44 and 46 extends beyond the horizontal length of the angle iron form to provide a bottom support arm as shown in bottom right support arm 64. The typical curb and grate inlet has a permanent basin bar 66 that extends across the basin in front of the curb inlet parallel with the curb. When my invention is in place, the support bars are placed so that the extended support arms are located inside the continuous bar sleeve 50 and extend under the basin bar 66 into the curb inlet 60. They hold the continuous bar sleeve along the upper peripheral edge of the filter basket in place against the outer inside walls of the curb inlet 60. The curb inlet side walls are unique from one inlet to another. This vertical angle of the lower support bars that extends under the basin bar 66 is made of flat sheet metal. These are easy to bend into shape in order to fit the large variety of curb inlet side walls. This bending is necessary only during an original installation. During replacement of the bag assembly, there would be no need to reshape the lower support bars because the entire support structure can be reused without alteration. A Pillow 67 can be placed within the filter basket to further remove pollutants by absorbing hydrocarbons. The extension of the lower support arms into inside the curb inlet and the holds the peripheral edge of the filter basket against the curb inlet side walls. This catches the storm water that flows from the street to behind the basin bar into the curb inlet and guides the storm water into inside the basin basket.

Insert With a Discontinuous Rod Support Structure

In the single discontinuous rod basin design shown in Figure V, the support structure consists of a single discontinuous support rod 80 of elongated material that is essentially rigid. In my preferred embodiment the support rod comprises one piece of #9 galvanized metal wire. This is essentially resistant to both wear and corrosion. The discontinuous metal rod bends essentially at the corners inside a rectangular inlet basin or bending in an essentially circular configuration inside a circular inlet basin. When formed to fit a basin, the rod has two ends that bend around and form an overlap 72 at each end.

The support rod is inserted into the rod sleeves 82 located on the upper peripheral lip of the bag assembly 78. The bag assembly comprises the rod sleeves 82 and the filter basket 74 suspended thereon. This combination of rod and sleeve rests directly upon the cover support ledge 84 and under the perforated basin cover 70 holding the apparatus in position on the cover supports. A basin support may consist of other support structures other than a ledge. For example the perforated basin cover might rest on bolts that extend out from the sides of the inlet basin walls. Across gaps in the cover support 86 additional reinforcement such as tubing or angle iron 76 may underprop the rod. A Pillow 67 may be placed within the filter basket to further remove pollutants by absorbing hydrocarbons.5

The Subgrate Basin Insert With Four Bars

The preferred embodiment of the subgrate basin insert with four bars comprises a support structure and a bag assembly 94 suspended thereon. The support structure consists multiple lengths of elongated essentially rigid material or in my preferred embodiment four support bars 100. The bag assembly comprises a filter basket 94 and four bar sleeves 102. The bars stretch the sleeves across a portion of the inlet cover support ledge 104. The four bar sleeves enclose four support bars 100. The combination of support bars and sleeves rest directly upon the cover support ledges 104 without any intervening structure. Frequently there are only two cover support ledges in the basin leaving gaps in the cover ledge 86 on the opposite sides of the rectangle. When there are gaps in the support angle, angle iron shaped support bars replace the essentially flat support bars 100, giving additional strength in order to span inlet basin sides. Each bar extends onto each of the two opposite ledges. Where the bars require extra strength to expand across the basin between gaps in the cover ledge 86 the support bars are made of 18 gage galvanized sheet metal in angle iron form as in support angle iron 76. The ends are then placed on the ledges and in a corner of the basin in order to hold the opposite bars in position. The support ledges are typically about two inches wide. In my preferred embodiment, the support rods are made of eighteen gage galvanized sheet metal two inches wide and about inch shorter than the length of the expansion across the basin, The filter basket is made of a porous material with hydraulic openings smaller than the pollutants intended to be filtered from the storm water. In my preferred embodiment, the bag assembly is made from a polypropylene geotextile fabric. However this filter may be made of many types of porous materials for example, cotton, burlap, or stainless steel, galvanized steel, fiberglass, and aluminum mesh. A Pillow 67 may be placed within the filter basket to further remove pollutants by absorbing hydrocarbons.

Bypass 92 is located in the insides of the filter basket under the bridge flap allowing storm water to flow easily out unhindered between the basket and the inlet basin walls. In my preferred embodiment the bridge is a flap extension of the bar sleeve. The bridge flap 96 conveys the storm water over the bypass opening and into the inside of the filter basket 94. The bridge flap 96 can comprise any suitable metal or fabric. In my preferred embodiment it is comprised of geotextile material and is an extension of the filter basket. A Pillow 67 may be placed within the filter basket to further remove pollutants by absorbing hydrocarbons.

Operation of my Invention

My invention removes and retains storm water pollutants within a storm water inlet basin 32, 68 and 88. Storm water flows from the street through the perforated basin cover 34, 70 and 90. Then it flows across a support structure inserted in its bar sleeves 48, 76, or rod sleeve 48. The storm water then flows into the filter basket 38, 74, and 94. The baskets' filter material permits storm water to flow through the filter basket and into the basin chamber while retaining pollutants within the filter basket. The filter's support structure comprises essentially rigid elongated material for support bars 44,46, 80, and 100 inserted inside the sleeves that hold the apparatus in position upon the cover support ledge 52, 84, and 104. The support bars inserted inside the sleeves rest below the perforated cover 34, 70, 90 and directly upon the basin cover support ledges. The sleeves also convey water from the adjacent opening rim of the inlet basin 32.68, and 88 onto the bridge flap 40, 71, and 96 into the interior of the filter basket 38,74, and 94. The support structure is connected to the bag assembly by inserting the rod or support bars into sleeves on the upper peripheral lip of the bag assembly. The bars place the weight of the filter basket upon the cover support, while preventing the deformation of the bag assembly. The support rods or bars form a rectangular or a circular pattern that is essentially as long as the length and width of the perforated basin cover. The ends of the support bars extend onto the opposite two ledges of the basin and prevent the bars from slipping past the cover support ledge into the basins' lower chamber. In the event of filter failure, or during high water flows, it is necessary for water to escape from the filter basket unhindered through a bypass channel. When the filter basket is made of flexible material it tends to hang in a circular formation and pulls away from the inlet basin at the basin corners. When the openings are located in the corners of the inlet basin the storm water has the maximum space to flow out of the filter basket into the inlet basin's lower chamber. A reliable by pass is needed so that the water does not back up into the street or parking lot and cause a traffic hazard. A Pillow 67 may be placed within the filter basket to further remove pollutants such as hydrocarbons by absorbing the pollutants.

The bridge flap 40, 71 and 96 is shown cut away to expose the bypass openings as shown in 36 and 92. The bridge flap conveys water from the sleeves over the by pass into inside the filter basket. This prevents the storm water from prematurely dropping through the by pass without first passing through the filter basket.

The present invention is convenient to install. In the insert for a grate and curb inlet combination as shown in Figure IV, first remove the perforated basin cover 34 from the basin inlet. Next bend the left support arm 62 on the end of the left support bar 46 until it follows snugly against the left inside of the curb inlet 60 when the support bar is laid on the left cover support ledge not shown but opposite cover support 52 and the left support bar is extended under the basin bar 66. The front of the bar should extend out of the sleeve about 1½ inches. Do the same on the right support bar 44 on the right cover support ledge 52. Insert the right and left support bars 44 and 62 with the bottom support arms 62 and 64 going first into the continuous bar sleeve 50. Insert the rear bar spreader 56 into the bar sleeve 48. Lay the partially assembled apparatus onto the cover support ledges with both of the bottom support arms extending inside the continuous bar sleeve under the basin bar 66 into the curb inlet 60. The upper lip of the filter basket loops between the right and left bottom support arms. The upper lip of the filter basket needs to be firm against only the sides of the curb inlet because this is where essentially all the storm water enters through the curb inlet opening. Lay the rear bar spreader between the rear ends of the support bars to keep them positioned upon the support ledges. Lay the front bar spreader 58 with the shorter side of the angle iron form down between the right and left support bars 44 and 46 forcing the support bars to stay in place in the sleeve upon the support ledges. A Pillow 67 can be placed within the filter basket to further remove pollutants by absorbing hydrocarbons. With the apparatus in position replace the perforated basin cover 34. To remove the apparatus reverse the order of the above procedure.

Installing a single rod design shown in Figure V, is also convenient. The rod 80 can be cut from a continuous inexpensive wire roll and custom fit on site. Bend the rod into a rectangular pattern so that it fits snugly into the four corners of the basin inlet 68. Beginning with one side, insert the rod 22 into the bar sleeves 48 until all four sleeves on all sides of the bag assembly 78 are inserted and slid around onto the full length of the rod. The last extension of the rod will be double within the sleeve because it includes the rod overlap 72. Once formed, the rod can be conveniently reused when renewing the bag assembly without rebending the rod. Next, insert the assembled apparatus inside the inlet basin 68 on the cover support ledge 84. Where the support ledges are on only two sides of the inlet basin, the sides with the gap in the cover ledge 86 may require additional support for the support rod. For this, cradle the support rod on angle iron 76 with the angle iron laying like an “L” so that the top of the “L” extends between the perforated basin cover and the basin inlets' opening. With the apparatus installed replace the perforated basin cover 90. To remove the apparatus reverse the order of the above procedure.

To install the rectangle design for the insert with corner bypasses as shown in Figure VI, first remove the perforated basin cover 90. Insert the four support bars 100 into the sleeves of the bag assembly 98. Then lay each inserted bar upon the four cover support ledges 104 in the inlet basin 88. Where there are only two parallel cover ledges use sheet metal formed into angle iron 76 to extend across support gap 86. Place the angle iron support bars resting the ends of the support bars upon the ledges in the basin corners so that the remaining two support bars are held in position upon the cover support ledges. With the apparatus in position replace the basin cover. To remove the apparatus reverse the order of the above procedure.

Servicing the filter insert is convenient. They can be either vacuumed out or the entire apparatus pulled out by hand and emptied. If the apparatus is vacuumed the bag assembly needs to be rigid to resist the suction of the vacuum. The filter basket may include a semi rigid perforated reinforcement within the filter basket that resists deformation especially during maintenance. The bag assembly can be made more rigid with reinforcement such as a wire screen either built into the bag assembly or laid within the filter basket.

Accordingly the reader will see that this invention can be used to remove pollutants from storm water within an inlet basin before the water is released down stream from the basin. One can also see that it is economical to manufacture, install and service. Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. 

1 I claim in a storm water inlet basin a) with a combination of a curb inlet and a perforated cover, b) that rests on a cover support within a storm water inlet basin, c) with a filter basket assembly located essentially beneath said perforated cover, d) a support means to hold said filter basket assembly in position within said inlet basin comprising a combination of support bars, a bar sleeve and a continuous bar sleeve formed in the upper peripheral edge of the filter basket assembly wherein said combination rests directly upon said cover support, and further said support bars hold a portion of said continuous bar sleeve in place essentially against the inside outer walls of said curb inlet by means of support arms, and further the support bars also hold portions of the continuous bar sleeve in place along cover supports. 2 Said support means of claim 20 further comprising a front and rear spreader bar that hold the right and left support bars in position upon the cover support ledges. 3 The support means of claim 20 further comprising a front spreader bar and a bypass bridge. 4 The filter basket of claim 20 further comprising a semi rigid perforated reinforcement within the filter basket that resists deformation during maintenance. 5 I claim in a storm water inlet basin comprising a) a perforated cover that rests upon b) a cover support within a top opening of a storm water inlet basin with c) a basin insert located below said inlet basin's perforated cover and essentially within said inlet basin, d) a support structure with a filter basket assembly suspended thereon wherein said support structure consists of elongated essentially rigid material inserted into one or more sleeves formed on an upper periphery portion of said filter basket wherein said ridged material stretches said sleeve along the cover support and lays the combination of said sleeves and said essentially rigid material directly upon said cover support holding the filter basket in place within said inlet basin. 6 The support structure of claim 24 wherein said elongated essentially rigid material is a discontinuous metal rod that bending essentially at the corners at the cover supports inside a rectangular inlet basin or bending at the cover supports in an essentially circular configuration inside a circular inlet basin. 7 The said discontinuous rod of claim 25 further comprising two open ends that overlap. 8 Said support structure of claim 25 wherein the elongated essentially rigid material is underpropped across gaps in the cover support by additional reinforcement such as but not limited to tubing or sheet metal in angle iron form 9 Said filter bag assembly of claim 24 further comprising a semi rigid perforated reinforcement within the filter basket that resists bag deformation. 10 The support structure of claim 24 comprising multiple lengths of the elongated essentially rigid material. 11 The elongated essentially rigid material of claim 24 comprising sheet metal. 12 The basin insert of claim 24 comprising one or more filter bypasses and a by pass bridge to channel storm water over the bypass opening into inside the filter basket. 13 The by passes of claim 32 located essentially in the corners of the inlet basin. 44 The bridge of claim 32 consisting of a flap extension to said sleeve of the bag assembly. 